ullage noun & verb. ['ʌlɪdʒ] LME.
[Anglo-Norman ulliage (cf. Anglo-Latin oillagium, ull-) = Old French eull
i. age (French ouillage), from euillier (French ouiller) fill (a barrel) (cf. Anglo-Latin oillare) from Proto-Gallo-Romance verb from Latin oculus eye, used in the sense of bung-hole: see -AGE.]
A. noun.
1. The amount of wine etc. by which a cask or bottle falls short of being full after leakage, evaporation, or use. LME.
on ullage (of a cask etc.) not full; partly used.
■ F. Marryat I held the bottle up to the candle to ascertain the ullage.
b. The part of a fuel tank in a vehicle, esp. a rocket, not filled with fuel; the capacity of this part. M20.

2. a. The amount of wine etc. remaining in a cask after leakage, evaporation, and use. M19.
b. The dregs remaining in a glass etc. slang. L19.

3. transf. A useless or worthless member of a ship's crew. Nautical slang. E20.

Comb.:
ullage rocket Astronautics an auxiliary rocket used in weightless conditions to provide sufficient acceleration to force a liquid propellant to the end of its tank and ensure a continuous fuel supply.
b. verb trans.
1. Calculate the amount of ullage in (a cask). M18.

2. Reduce or increase the level in (a cask etc.) L19.

■ ullaged adjective (a) (of a cask or bottle) not full; (b) (of wine) affected in quality by ullage: M16.

[TahlilGaran] English Dictionary ▲